A method of producing a display panel such as a liquid crystal panel included in a display device as described below has been known. A pair of substrates one of which includes a thin film pattern of semiconductor elements such as thin film transistors (TFTs) is prepared. The substrates are bonded to each other via a sealing agent portion surrounding the thin film pattern and bonded substrates are cut along an outline of the display panel and a display panel is produced.
For example, Patent Document 1 describes a method of producing a liquid crystal panel in which liquid crystals are injected to a space between the substrates that are bonded via the sealing agent and the bonded substrates are cut to obtain liquid crystal panels. In such a producing method, the substrates in a pair are cut along a substantially straight cutting line together with the sealing agent with a dicing method such that cut surfaces of the substrates and a cut surface of the sealing agent are aligned with each other. Therefore, the width dimension of the sealing agent is decreased after cutting the substrates and a frame width of the display panel to be produced is decreased.